1. Field
The present disclosure relates generally to aircraft and, in particular, to an aircraft tracking system. More specifically, the present disclosure relates to a method and apparatus for controlling operation of an aircraft tracking system.
2. Background
Many aircraft carry systems that provide broadcasts of aircraft location for tracking and emergency location purposes. Aircraft systems that provide tracking or an emergency location function include distress radio beacons such as emergency locator transmitters (ELTs), transponder systems such as the Automatic Dependent Surveillance-Broadcast (ADS-B) systems, aircraft communication systems implementing Aircraft Communications Addressing and Reporting System (ACARS) based position reporting systems and specialized tracking systems providing dedicated communications links and tracking capabilities. These existing tracking and emergency location systems respond to a variety of control inputs to determine their reporting rates and the content of their reports is generally responsive to some combination of flight crew inputs, aircraft state inputs and, in some cases, ground based command inputs.
Emergency locator transmitters systems allow for activation and deactivation of distress beacons by crew members of the aircraft. Emergency locator transmitters include internal sensors to detect high temperatures and high decelerations indicative of a crash and use these to automatically trigger transmissions. These automatically triggered transmissions can be deactivated by the crew of the aircraft. For example, if transmissions are set off by a hard landing, they may be deactivated by the crew. The system may use aircraft inputs to provide aircraft location data in the distress broadcasts but are otherwise autonomous. These systems do not have ground based command inputs. In next generation emergency locator transmitters, which are desired to be more tamper proof, it is also desirable to use aircraft state data to trigger broadcasts prior to an incident.
Transponder systems such as the Automatic Dependent Surveillance-Broadcast (ADS-B) broadcast aircraft location and state data to ground based, airborne or satellite based receivers. These systems allow a crew member to enter distress codes. These systems have no autonomy and are completely dependent on other aircraft systems. In some cases, these systems allow the crew members to turn off the overall system to stop the position broadcasts.
Specialized aircraft tracking systems can use existing or dedicated aircraft radio or satellite communications links to send periodic aircraft position reports. These systems also may be programmed to use aircraft state and position information from aircraft avionics systems to trigger higher reporting rates and incident reports. These systems typically support crew activation and deactivation and ground based commands. These systems may have internal sensors to detect aircraft position and state variables. These existing systems may have limited tamper-proofing functions and may have varying responsiveness to crew member and ground control inputs.
Limitations for these existing systems include having limited or no autonomy from other aircraft systems, providing limited or no functions to prevent the flight crew from disabling the tracking functionality, such as tamper-proofing, the lack of the ability of significant system stakeholders such as crew members of the aircraft, ground controllers, or a combination thereof to trigger transmissions, limited or no ability to autonomously detect and trigger broadcasts on indications of aircraft abnormal conditions and providing limited or no support for higher level system control options.
Therefore, it would be desirable to have a method and apparatus that take into account one or more of the issues discussed above, as well as other possible issues. For example, it would be desirable to have a method and apparatus that overcome a technical problem with tampering with emergency locator transmitters. As another example, it would be desirable to have a method and apparatus that overcome a technical problem the economy in controlling reporting information about aircraft.